scholarly journals ELECTROCHEMISTRY OF IMMOBILIZED MICROPARTICLES AND MICRODROPLETE: ACCESS TO FUNDAMENTAL DATA OF SOLID MATERIALS AND IONS

2021 ◽  
Vol 87 (9) ◽  
pp. 55-60
Author(s):  
Fritz Scholz
Keyword(s):  
General Interest ◽  
Ion Transfer ◽  
Free Energies ◽  
Solid Materials ◽  
Common Features ◽  
Three Phase ◽  
Cooperation Partners ◽  
First Time ◽  
Electrode Technique

The idea to study the electrochemistry of immobilized microparticles has been published by this author for the first time in 1989. In the last 32 years, this approach has been shown to be very successful not only for analytical characterization of solid materials, but also applicable to extract thermodynamic and kinetic data, and even to determine the age of metal specimen. In 2000, it has been shown that the electrochemistry of immobilized microdroplets gives an elegant access to determine the Gibbs free energies of ion transfer between immiscible solvents. These measurements are performed with a standard 3-electrode potentiostate and can be used also for solvents, which cannot be used in experiments with the classical 4-electrode technique. The electrochemistry of microparticles and microdroplets share several common features with respect to the electrode mechanisms: in both cases three-phase electrodes are realized and ion and electron transfer proceed simultaneously. This talk reviews the activities of the speaker and his cooperation partners during the last 3 decades paying special attention to those results, which are of general interest.

Contributions to the mechanisms of mitosis and roles of cytoplasmic microtubules from ultrastructural analyses of fungi

1978 ◽  
Vol 36 (2) ◽  
pp. 266-267
Author(s):  
I. Brent Heath
Keyword(s):  
Nuclear Envelope ◽  
Direct Application ◽  
Ultrastructural Analysis ◽  
General Interest ◽  
Research Results ◽  
Organelle Motility ◽  
Cytoplasmic Microtubules

Detailed ultrastructural analysis of fungal mitotic systems and cytoplasmic microtubules might be expected to contribute to a number of areas of general interest in addition to the direct application to the organisms of study. These areas include possibly fundamental general mechanisms of mitosis; evolution of mitosis; phylogeny of organisms; mechanisms of organelle motility and positioning; characterization of cellular aspects of microtubule properties and polymerization control features. This communication is intended to outline our current research results relating to selected parts of the above questions.Mitosis in the oomycetes Saprolegnia and Thraustotheca has been described previously. These papers described simple kinetochores and showed that the kineto- chores could probably be used as markers for the poorly defined chromosomes. Kineto- chore counts from serially sectioned prophase mitotic nuclei show that kinetochore replication precedes centriole replication to yield a single hemispherical array containing approximately the 4 n number of kinetochore microtubules diverging from the centriole associated "pocket" region of the nuclear envelope (Fig. 1).

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

Three-Phase Electrochemistry of a Highly Lipophilic Neutral Ru-Complex Having a Tridentate Bis(benzimidazolate)pyridine Ligand

2020 ◽  
Author(s):  
Vishwanath R.S ◽  
Masa-aki Haga ◽  
Takumi Watanabe ◽  
Emilia Witkowska Nery ◽  
Martin Jönsson-Niedziolka
Keyword(s):  
Redox Potential ◽  
Organic Phase ◽  
Electron Donor ◽  
Ion Transfer ◽  
Neutral Complex ◽  
Pyridine Ligand ◽  
Electrochemical Testing ◽  
Ru Complex ◽  
Three Phase ◽  
Exceptional Stability

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [Ru<sup>II</sup>(LR)(L)]<sup>0</sup> (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [Ru<sup>II</sup>(LR)(L)]<sup>0</sup> shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl<sup>−</sup>. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

Three-Phase Electrochemistry of a Highly Lipophilic Neutral Ru-Complex Having a Tridentate Bis(benzimidazolate)pyridine Ligand

2020 ◽  
Author(s):  
Vishwanath R.S ◽  
Masa-aki Haga ◽  
Takumi Watanabe ◽  
Emilia Witkowska Nery ◽  
Martin Jönsson-Niedziolka
Keyword(s):  
Redox Potential ◽  
Organic Phase ◽  
Electron Donor ◽  
Ion Transfer ◽  
Neutral Complex ◽  
Pyridine Ligand ◽  
Electrochemical Testing ◽  
Ru Complex ◽  
Three Phase ◽  
Exceptional Stability

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [Ru<sup>II</sup>(LR)(L)]<sup>0</sup> (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [Ru<sup>II</sup>(LR)(L)]<sup>0</sup> shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl<sup>−</sup>. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

Three-Phase Electrochemistry of a Highly Lipophilic Neutral Ru-Complex Having a Tridentate Bis(benzimidazolate)pyridine Ligand

2020 ◽  
Author(s):  
Vishwanath R.S ◽  
Masa-aki Haga ◽  
Takumi Watanabe ◽  
Emilia Witkowska Nery ◽  
Martin Jönsson-Niedziolka
Keyword(s):  
Redox Potential ◽  
Organic Phase ◽  
Electron Donor ◽  
Ion Transfer ◽  
Neutral Complex ◽  
Pyridine Ligand ◽  
Electrochemical Testing ◽  
Ru Complex ◽  
Three Phase ◽  
Exceptional Stability

Here we describe the synthesis and electrochemical testing of a heteroleptic bis(tridentate) ruthenium(II) complex [Ru<sup>II</sup>(LR)(L)]<sup>0</sup> (LR =2,6-bis(1-(2-octyldodecan)benzimidazol-2-yl)pyridine, L = 2,6-bis(benzimidazolate)pyridine). It is a neutral complex which undergoes a quasireversible oxidation and reduction at relatively low potential. The newly synthetized compound was used for studies of ion-transfer at the three-phase junction because of the sensitivity of this method to cation expulsion. The [Ru<sup>II</sup>(LR)(L)]<sup>0</sup> shows exceptional stability during cycling and is sufficiently lipophilic even after oxidation to persist in the organic phase also using very hydrophilic anions such as Cl<sup>−</sup>. Given its low redox potential and strong lipophilicity this compound will be of interest as an electron donor in liquid-liquid electrochemistry.

Chemical Constituents and Antibacterial Activity of Cissus Aralioides.

2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang
Keyword(s):  
Plant Extract ◽  
Chemical Constituents ◽  
Ethyl Acetate Fraction ◽  
Antibacterial Activities ◽  
Sub Saharan Africa ◽  
Chromatographic Purification ◽  
Whole Plant ◽  
Sub Saharan ◽  
First Time

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.

Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar
Keyword(s):  
Green Synthesis ◽  
Color Change ◽  
Limit Of Detection ◽  
Aqueous Media ◽  
Suitable Condition ◽  
Cost Effective ◽  
Spectroscopic Studies ◽  
Calibration Plot ◽  
First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

scholarly journals Waste-Based One-Part Alkali Activated Materials

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2911
Author(s):  
Margarida Gonçalves ◽  
Inês Silveirinha Vilarinho ◽  
Marinélia Capela ◽  
Ana Caetano ◽  
Rui Miguel Novais ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Microstructural Analysis ◽  
Construction Materials ◽  
Sodium Metasilicate ◽  
High Compressive Strength ◽  
Hardened State ◽  
First Time ◽  
Furnace Slag ◽  
Alkali Activated

Ordinary Portland Cement is the most widely used binder in the construction sector; however, a very high carbon footprint is associated with its production process. Consequently, more sustainable alternative construction materials are being investigated, namely, one-part alkali activated materials (AAMs). In this work, waste-based one-part AAMs binders were developed using only a blast furnace slag, as the solid precursor, and sodium metasilicate, as the solid activator. For the first time, mortars in which the commercial sand was replaced by two exhausted sands from biomass boilers (CA and CT) were developed. Firstly, the characterization of the slag and sands (aggregates) was performed. After, the AAMs fresh and hardened state properties were evaluated, being the characterization complemented by FTIR and microstructural analysis. The binder and the mortars prepared with commercial sand presented high compressive strength values after 28 days of curing-56 MPa and 79 MPa, respectively. The mortars developed with exhausted sands exhibit outstanding compressive strength values, 86 and 70 MPa for CT and CA, respectively, and the other material’s properties were not affected. Consequently, this work proved that high compressive strength waste-based one-part AAMs mortars can be produced and that it is feasible to use another waste as aggregate in the mortar’s formulations: the exhausted sands from biomass boilers.

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